Lesson 12

This lesson helps learners understand how scientific theories gain strength from evidence, prediction and testability, while remaining open to revision. Through discussion, comparison activities and two key astronomy case studies, learners examine why theories change, how limitations drive new discoveries and why scientific knowledge develops over time. Emphasise that a scientific theory is not a guess, encourage evidence-based explanations and use questioning throughout to check that learners can distinguish a theory’s strengths from its limitations.